THE ARISING · Longevity & Healthspan
FDA Orders Vision-Loss Warning on Every GLP-1 Drug Label
The FDA is requiring every maker of a GLP-1 receptor agonist to add a warning about a rare eye condition that can cause sudden, painless vision loss in one eye.
The condition is called nonarteritic anterior ischemic optic neuropathy, or NAION. It involves reduced blood flow to the optic nerve, which carries signals from the eye to the brain. According to the FDA's drug safety communication, cases have been reported for all currently marketed GLP-1 therapies.
The agency began its review after a 2024 study in JAMA Ophthalmology, led by Jimena Tatiana Hathaway, found a potential link between semaglutide and NAION.
The FDA then pooled data from 126 clinical trials of GLP-1 drugs. Among 78,217 patients who received a GLP-1 therapy, there were 10 probable cases of NAION. Among 56,036 patients who received a comparator, there were five probable cases, all in people on placebo. None appeared in those taking a non-GLP-1 glucose-lowering drug.
That works out to 6.4 events per 100,000 person-years with GLP-1 therapy, against 3.8 per 100,000 person-years with a comparator, according to the communication.
The FDA also ran a retrospective cohort study using its Sentinel data network. It followed people with type 2 diabetes who started a GLP-1 drug, an SGLT2 inhibitor or a DPP-4 inhibitor between 2019 and 2024. GLP-1 users had a higher risk of NAION than those on a DPP-4 inhibitor. The difference against SGLT2 inhibitor users was not statistically significant.
For people taking these drugs, the FDA's guidance centers on speed. Health care professionals should tell patients to report immediately any sudden, painless drop in vision, loss of part of the visual field, or visual disturbance in one eye. If NAION is suspected, the FDA wrote, "promptly refer the patient to an ophthalmologist for evaluation." It added: "Consider discontinuing the GLP-1 receptor agonist in patients who develop NAION, unless the benefits of treatment clearly outweigh the risk."
The FDA describes a potential increased risk, not a proven causal mechanism. Patients who experience sudden visual symptoms should contact their health care professional right away and discuss treatment changes with them.